Typically, the generation of an ultor or high voltage is accomplished in a flyback transformer which is included in a horizontal deflection circuit. Beam current variations cause modulations of the peak current in a primary winding of the flyback transformer and of the high voltage. Modulation of the primary winding current could produce undesired deflection current modulation. Disadvantageously, high voltage variations may alter the deflection sensitivity and result in raster size variations.
An East-West correction circuit is typically used for correcting outside pincushion distortion. U.S. Pat. No. 5,841,248, entitled, CHARGE CONTROLLED RASTER CORRECTION CIRCUIT in the name of Haferl, et al. (the Haferl, et al. patent) describes an East-West correction circuit that reduces the aforementioned effects of high voltage variations by using an isolating diode coupled between a primary winding of a flyback transformer and an East-West modulation transistor. The East-West modulation transistor is coupled in series with a horizontal output transistor and with the isolating diode.
In a deflection circuit requiring an inside pincushion distortion correction, a trace resonant circuit is, typically, included for modulating the deflection current. An example of an arrangement that includes a resonant circuit for providing inside pincushion distortion correction is shown in U.S. Pat. No. 5,115,171, entitled RASTER DISTORTION CORRECTION CIRCUIT, in the name of Haferl (the Haferl patent). It may be desirable to employ in a deflection circuit having an isolating diode such as described in, for example, the Haferl, et al. patent, a trace resonant circuit that provides inside pincushion distortion correction.